DIY Coil Denitrator

2.  Drop your coils into the cylinder next.

I use pre-coiled airline tubing from WalMart. 50’ is around $7.00 and is found in their hardware department. The bright yellow color is inert and will not impact your livestock. Also, the inside diameter is perfect for this project! ¼” ID is ideal  but you can go up to a 3/8” ID if you prefer. Remember, the unit is sealed and cannot be cleaned once finished!

Please note that you’ll have to cut the brass air pressure fittings off both ends of the coils prior to dropping into the PVC cylinder! The bottom cut-end of the coils simply rests at the bottom of the cylinder, unattached to anything. The top cut-end of the coils will be attached later to the nipple fitting attached to the lid.

Now we insert the bio-media down inside the coils that have been installed into the cylinder. This is probably the most important decision-making in the entire project! The quality of the media and the available surface area will determine the ultimate success of your denitrator.  Afterall, it will be the ability of the bacteria colonies to expand and contract as the food source increases and decreases, that will ultimately contribute to those lower nitrate concentrations.

I used BioKaskades, (small) in my prototype reactor but any good spiked ball or BioPak will do. Avoid DLS or other mat-type materials as these clog and hold detritus much too easily. I would also caution against any scintered glass medias. These have phenomenal surface area but again, are so closed-cell that clogging could be an issue over time.

Once the inner area has been loaded with your choice of media, it is time to attach the top, cut-off end of the coiled tubing to the intake nipple.

Drill 2 holes into the top lid BEFORE attaching to the main cylinder body. Install 2 nipples or fittings that will accommodate the size of tubing used inside the cylinder. Nylon or vinyl fittings must be used!

Remember that the unit will be slightly pressurized once completed and running.  Insure all glue joints and fittings are secure and water-tight! I used pipe tape on the threads of my 2 fittings and really torqued them into the lid before sealing with epoxy cement.

Once cured, purple dope the inside of the lid lip and the top ½” outside of the cylinder. Once dry, apply PVC cement as you did to the bottom cap and install the lid to the tube. Your denitrator is complete!

Back to the beginning.

Click on each of the DIY Coil Denitrator components below to see the enlarged views and pertinent information.

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